The use of pulsed electric fields (PEF) for the treatment of food products is known. It is in particularly known to destroy micro-organisms with high voltage bipolar pulses. In U.S. Pat. No. 5,549,041 for example is disclosed a method for inactivating microorganisms in solid and semi-solid food products by treating the food products with high voltage electric pulses of 20-100 kV/cm. In the process of U.S. Pat. No. 5,549,041, the food product is placed in a treatment chamber with horizontal electrodes and the pulses have a very high frequency, i.e. a short pause time between two pulses, and are preferably changing polarity. In U.S. Pat. No. 5,690,978 is disclosed a process wherein a continuous flow of liquid food product is subjected to a high voltage electric field treatment in order to inactivate vegetative and bacterial spore microorganisms.
It is further known to use PEF as a non-thermal treatment for altering the texture of food products. In WO 2006/121397 a process for the treatment of potatoes and other root vegetables with electric pulses is disclosed, wherein the strength of the electric field applied is such that pores are created in the membranes of the plant cellular material (electroporation). Thus, the mechanical stress during a subsequent cutting or slicing step is reduced. The process of WO 2006/121397 is a continuous process using a relatively low electric field strengths of 0.2-10 kV/cm, low number of pulses of 1-500, and relatively low temperatures. Under these process conditions, starch does not yet gelatinise, such that no cooking is accomplished. WO 2011/139144 describes PEF cooking using field strengths of 0.2-20 kV/cm and up to 10000 pulses.
Using PEF to cause electroporation of cell membranes of potatoes is also known from Lebkova et al. (J. Food Eng 2005, 69, 177-184). PEF is performed in the absence of ohmic heating, and no cooking to obtain a ready-to-eat food product is accomplished.